Any updates on differences between IS and RC F? I'm curious as I was surprised at how differently my GS 350 drives compared to my Dad's LS 460 as both are on distantly related platforms (New N platform vs N platform). I guess the RC is a bit of a mishmash between several platforms, but still technically on New N I believe, so I wonder how the IS compares to the RC as both are on New N.
Thanks for the question. The 3IS chassis is essentially a shortened version of your 4GS platform. I have not had a chance yet to write a detailed review and post it up, but I do have a lot of experience with the OEM IS350 F-Sport now and have been driving my RCF again in the last few weeks a few times even back to back. RCF chassis/suspension is further 70% different from the base RC chassis so basically my comparison is of an IS350 F-Sport vs the RCF. It is actually hard to compare them since they are so different in their execution.
Back many years ago, I drove both RC350 F-Sport and IS350 F-Sport back to back. However, RCF is about 70% different from an RC with its own suspension, axles etc. so now I can only really compare the RCF fairly to the IS350. I might have to explain it in a full review, but in reality the RCF feels over-engineered compared to the IS350 F-Sport, which feels a lot more simpler in its execution. What people refer to "Frankenstein", is actually one of the strongest features of the car as it was developed to keep compact coupe dimensions while achieving a much higher level of torsional/lateral rigidity than was possible with the IS/GS platform. That was for the track purposes. It is something that is obvious going over asymmetrical loads over uneven surfaces where the IS350 has some cowl shake, vibrations/shuddering and jiggle while the RCF remains one solid unit even when it is an asymmetrical surface. It seems almost impossible to detect vibrations in the RCF chassis over any surface.
While IS350 F-Sport drives great up until 3/1t0h or 5/10th in the city, the RCF feels wider and heavier in part due to the steering programming of the EPS being more rigid/heavier/direct in SPORT+ mode and the bigger wheels and tires etc. Also, it is something like 200 lbs heavier so at slow speeds, the weight difference does seem to be apparent. However, once both cars are pushed past 5/10th up to 8/10th or so, the RCF completely separates itself and shrinks rapidly around the driver. While the IS350 F-Sport starts to struggle a bit and become bouncy/floaty over rapidly changing as the AVS tries to negotiate the rapidly changing surfaces by controlling the spring motion, the RCF with a lot more rigidity, it almost feel over-damped in terms of strong rebound control where the chassis stomps over the rapidly changing surface with a lot of authority. I believe, Lexus said, the RCF is supposed to 50% stiffer than the IS/GS platform in their press release. One can totally feel it. Should come as no surprise that the RCF is obviously a lot more stiffer due the suspension and chassis tuned for the track in the RCF compared to the IS350 F-Sport and can cause some head bobbling when going fast over un-even roads, but the body control and confidence one gets is just next level.
Again, I have to write a detailed review to give more context, but Lexus put a lot of engineering from performance perspective into the RCF and driving both back to back, the 30 - 40% higher price of the RCF seems to be put into perspective when pushed to the limit it was designed for. I really enjoy the IS350 F-Sport on the streets driving on normal roads as much as the RCF. They both are so different that it is not a fair comparison. The IS is a lot of fun up to 5/10th and 6/10th especially zipping around street turns and accelerations on city roads etc. Handles really well and 311 HP is a lot more than one needs. RCF seems a bit out of place for that type of driving due to how wide it is and the IS350 F-Sport feels nearly as much fun at slow speeds, but once you get some room to work with where RCF could be pushed past 5/10th, it really starts to dominate the experience. It simply feels like a car that is an overkill on the street with that level of performance, which is barely usable on the streets. That is what actually makes it feel even more special to experience such savagery in small doses.
Anyway, those are my impressions of ownership for both of them. I am very happy with both of them in their own unique ways. Let me know if you have any further questions. Cheers!
